From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Philipp Subject: Re: [PATCH V2] Btrfs-progs: add "btrfs subvolume get-default" subcommand Date: Mon, 11 Jul 2011 16:11:21 +0200 Message-ID: <4E1B0489.8030703@gmail.com> References: <1310374571-20811-1-git-send-email-xin.zhong@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-btrfs@vger.kernel.org, Hugo Mills To: "Zhong, Xin" Return-path: In-Reply-To: <1310374571-20811-1-git-send-email-xin.zhong@intel.com> List-ID: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Would you mind rebasing your patch on Hugo Mills' integration-branch for btrfs progs at http://git.darksatanic.net/repo/btrfs-progs-unstable.git integration-20110705 since it does not apply on top of all changes which are already there. Additionally, I spotted one whitespace error in the patch and marked it below. Thanks, Andreas Philipp On 11.07.2011 10:56, Zhong, Xin wrote: > Add subcommand to get the default subvolume of btrfs filesystem > > Reported-by: Yang, Yi > Signed-off-by: Zhong, Xin > --- > btrfs-list.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-- > btrfs.c | 3 +++ > btrfs_cmds.c | 31 ++++++++++++++++++++++++++++++- > btrfs_cmds.h | 3 ++- > 4 files changed, 90 insertions(+), 4 deletions(-) > > diff --git a/btrfs-list.c b/btrfs-list.c > index 93766a8..aa6a9b4 100644 > --- a/btrfs-list.c > +++ b/btrfs-list.c > @@ -536,7 +536,7 @@ build: > return full; > } > > -int list_subvols(int fd) > +int list_subvols(int fd, int get_default) > { > struct root_lookup root_lookup; > struct rb_node *n; > @@ -545,10 +545,12 @@ int list_subvols(int fd) > struct btrfs_ioctl_search_key *sk = &args.key; > struct btrfs_ioctl_search_header *sh; > struct btrfs_root_ref *ref; > + struct btrfs_dir_item *di; > unsigned long off = 0; > int name_len; > char *name; > u64 dir_id; > + u64 subvol_id = 0; > int i; > > root_lookup_init(&root_lookup); > @@ -642,6 +644,52 @@ int list_subvols(int fd) > n = rb_next(n); > } > > + memset(&args, 0, sizeof(args)); > + > + /* search in the tree of tree roots */ > + sk->tree_id = BTRFS_ROOT_TREE_OBJECTID; > + > + /* search dir item */ > + sk->max_type = BTRFS_DIR_ITEM_KEY; > + sk->min_type = BTRFS_DIR_ITEM_KEY; > + > + sk->max_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID; > + sk->min_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID; > + sk->max_offset = (u64)-1; > + sk->max_transid = (u64)-1; > + > + /* just a big number, doesn't matter much */ > + sk->nr_items = 4096; > + > + /* try to get the objectid of default subvolume */ > + if(get_default) { > + ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args); > + if (ret < 0) { > + fprintf(stderr, "ERROR: can't perform the search\n"); > + return ret; > + } > + > + off = 0; > + /* go through each item to find dir item named "default" */ > + for (i = 0; i < sk->nr_items; i++) { > + sh = (struct btrfs_ioctl_search_header *)(args.buf + > + off); > + off += sizeof(*sh); > + if (sh->type == BTRFS_DIR_ITEM_KEY) { > + di = (struct btrfs_dir_item *)(args.buf + off); > + name_len = le16_to_cpu(di->name_len); > + name = (char *)di + sizeof(struct btrfs_dir_item); > + if (!strncmp("default", name, name_len)) { > + subvol_id = btrfs_disk_key_objectid( > + &di->location); > + break; > + } > + } > + > + off += sh->len; > + } > + } > + > /* now that we have all the subvol-relative paths filled in, > * we have to string the subvols together so that we can get > * a path all the way back to the FS root > @@ -650,7 +698,12 @@ int list_subvols(int fd) > while (n) { > struct root_info *entry; > entry = rb_entry(n, struct root_info, rb_node); > - resolve_root(&root_lookup, entry); > + if(!get_default) > + resolve_root(&root_lookup, entry); > + /* we only want the default subvolume */ > + else if(subvol_id == entry->root_id) > + resolve_root(&root_lookup, entry); > + This line adds a whitespace error. > n = rb_prev(n); > } > > diff --git a/btrfs.c b/btrfs.c > index 46314cf..6b73f88 100644 > --- a/btrfs.c > +++ b/btrfs.c > @@ -73,6 +73,9 @@ static struct Command commands[] = { > "Set the subvolume of the filesystem which will be mounted\n" > "as default." > }, > + { do_get_default_subvol, 1, "subvolume get-default", "\n" > + "Get the default subvolume of a filesystem." > + }, > { do_fssync, 1, > "filesystem sync", "\n" > "Force a sync on the filesystem ." > diff --git a/btrfs_cmds.c b/btrfs_cmds.c > index 8031c58..11c56f6 100644 > --- a/btrfs_cmds.c > +++ b/btrfs_cmds.c > @@ -301,7 +301,7 @@ int do_subvol_list(int argc, char **argv) > fprintf(stderr, "ERROR: can't access '%s'\n", subvol); > return 12; > } > - ret = list_subvols(fd); > + ret = list_subvols(fd, 0); > if (ret) > return 19; > return 0; > @@ -834,6 +834,35 @@ int do_set_default_subvol(int nargs, char **argv) > return 0; > } > > +int do_get_default_subvol(int nargs, char **argv) > +{ > + int fd; > + int ret; > + char *subvol; > + > + subvol = argv[1]; > + > + ret = test_issubvolume(subvol); > + if (ret < 0) { > + fprintf(stderr, "ERROR: error accessing '%s'\n", subvol); > + return 12; > + } > + if (!ret) { > + fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol); > + return 13; > + } > + > + fd = open_file_or_dir(subvol); > + if (fd < 0) { > + fprintf(stderr, "ERROR: can't access '%s'\n", subvol); > + return 12; > + } > + ret = list_subvols(fd, 1); > + if (ret) > + return 19; > + return 0; > +} > + > int do_df_filesystem(int nargs, char **argv) > { > struct btrfs_ioctl_space_args *sargs; > diff --git a/btrfs_cmds.h b/btrfs_cmds.h > index 7bde191..9cf1ca1 100644 > --- a/btrfs_cmds.h > +++ b/btrfs_cmds.h > @@ -28,7 +28,8 @@ int do_scan(int nargs, char **argv); > int do_resize(int nargs, char **argv); > int do_subvol_list(int nargs, char **argv); > int do_set_default_subvol(int nargs, char **argv); > -int list_subvols(int fd); > +int do_get_default_subvol(int nargs, char **argv); > +int list_subvols(int fd, int get_default); > int do_df_filesystem(int nargs, char **argv); > int find_updated_files(int fd, u64 root_id, u64 oldest_gen); > int do_find_newer(int argc, char **argv); -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQIcBAEBAgAGBQJOGwSIAAoJEJIcBJ3+XkgiWBsP/2wV25KV8h+k3vD0DcttepMD hnoG1uIcDtCR+bqPGt5Lu/IQBeH2UhYfxTS5Hpn8sjqC44KxfeSCxHXBYOVreVw+ xMCJjXp+tIddO/BlF/dcN/anrL22vbawFKEV+kfofYvC00BQ7Mz2Uz28/N+hStV4 NuTHRdxDzROO7cHXu90RjfmuAjnkNd32uaQjiBpDJGcLbT4Mg6NsSmF23gcTr31X FzklXi5PyXKHksy+UTdzMfi0s2b/ss12hzlWPWydWlSPsCiGeuNJF5s/Dis+o4K3 1YxZYGB7JsK84CGXZhvdLlUcsM8ZxSZQySiCDhsbf27rpv3/waMfG73n8DsESbFr 3uyXodGUEiJgz5dVVwLEu1Pzo7sfJtjm7/LGm0xv+uKqzYc3omQmrbIyAQsvC3bK 6DY2FDx701jGf4LjfY4k0JQBCGzOL9hCqHwaXqNxh9gHSOkFU7jtaVgpCbo0uttd IGaY1vS4DIBzrFJjpN78rIdIwSKPJpgXbY7ONHIluQJOx0IW2mU+dQAVI1VuNmXp shdQ4MEuPLg7rdKKFyOhJlasvJqmc1zgPAoDz4TjFEwSMvSijBEEo/ZbrHcpVydj unS6SeyrDfDLniiBy4O/c/7/GkeypVU/ggAxxAxcGT/fkB272j1OEc4OalukGVs/ 2fx83ZIAsN7jhzQMtDDu =lqbJ -----END PGP SIGNATURE-----